As is known in the art, the plane of polarization of polarized light rotates in a magnetic field when the light is propagated in a direction parallel to the direction of the magnetic field. This phenomenon is utilized by magneto-optical current transducers (MOCT), to optically measure the current flowing through a conductor. MOCTs are commonly used in electricity metering systems, and in particular, in power distribution sub-stations. For example, U.S. Pat. No. 4,578,639 describes a metering system employing an MOCT, and is hereby incorporated by reference in it's entirety. Generally, the MOCT includes an optical source (typically an LED). The light is passed through a collimating lens and a polarizer. The polarized light then travels through an optical path comprising a dielectric material, around a current carrying conductor. The light source is received at a detector, which is commonly a silicon diode. The received signal may then be conditioned and amplified for output.
Though MOCTs are well accepted and have proven to be very reliable, some drawbacks persist. For example, some MOCT based meters tend to exhibit erroneous non-zero energy meter registration during power outages. Thus, there is a need in the art for an MOCT that does not exhibit non-zero energy registration during power outages.